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Background Incomplete reperfusion (IR) after mechanical thrombectomy (MT) can be a consequence of residual occlusion, no-reflow phenomenon, or collateral counterpressure. Data on the impact of these phenomena on clinical outcome are limited. Methods Patients from the ESCAPE-NA1 trial with IR (expanded Thrombolysis In Cerebral Infarction (eTICI) 2b) were compared with those with complete or near-complete reperfusion (eTICI 2c-3) on the final angiography run. Final runs were assessed for (a) an MT-accessible occlusion, or (b) a non-MT-accessible occlusion pattern. The primary clinical outcome was modified Rankin Scale (mRS) 0--2 at 90 days. Our imaging outcome was infarction in IR territory on follow-up imaging. Unadjusted and adjusted incidence rate ratios (aIRR) with 95% confidence intervals (95% CI) were obtained. Results Of 1105 patients, 443 (40.1%) with IR and 506 (46.1%) with complete or near-complete reperfusion were included. An MT-accessible occlusion was identified in 147/443 patients (33.2%) and a non-MT-accessible occlusion in 296/443 (66.8%). As compared with patients with near-complete/complete reperfusion, patients with IR had significantly lower chances of achieving mRS 0--2 at 90 days (aIRR 0.82, 95% CI 0.74 to 0.91). Rates of mRS 0--2 were lower in the MT-accessible occlusion group as compared with the non-MT-accessible occlusion pattern group (aIRR 0.71, 95% CI 0.60 to 0.83, and aIRR 0.89, 95% CI 0.81 to 0.98, respectively). More patients with MT-accessible occlusion patterns developed infarcts in the non-reperfused territory as compared with patients with non-MT occlusion patterns (68.7% vs 46.3%). Conclusion IR was associated with worse clinical outcomes than near-complete/complete reperfusion. Two-thirds of our patients with IR had non-MT-accessible occlusion patterns which were associated with better clinical and imaging outcomes compared with those with MT-accessible occlusion patterns. [ABSTRACT FROM AUTHOR]

Background The benefit of endovascular thrombectomy (EVT) in stroke patients with a low baseline Alberta Stroke Program Early CT Score (ASPECTS, ≤5) is uncertain. We aim to use random forest regression modeling to predict 90 day home time in patients with low ASPECTS. Methods We used the Quality Improvement and Clinical Research (QuICR) provincial stroke registry and administrative data from southern Alberta to identify patients who underwent EVT in our center from July 2015 to November 2020. Baseline ASPECTS on non-contrast CT and CT angiography data were scored by a two physician consensus. The primary outcome was the predicted 90 day home time (the number of nights a patient is back at their premorbid living situation without an increase in level of care within 90 days of the stroke) using random forests regression. Estimates were generated using 200 bootstrapped datasets. Covariate contribution to home time was determined using partial dependence plots. Results Of 657 EVT patients, 85 (12.9%) had baseline ASPECTS ≤5 (mean age 70.9 years, 44.7% women, 93.9% good-moderate collaterals, 60% M1-middle cerebral artery occlusion). Using partial dependence estimates, mean predicted home times were similar in the low ASPECTS (44.3 days) versus higher ASPECTS (43.1) groups. Factors predicting lower 90 day home time in this population were diabetes mellitus (-8.8 days), hypertension (-5.7 days), and atrial fibrillation (-3.6 days). There was no meaningful difference in predicted 90 day home time by sex, baseline National Institutes of Health Stroke Severity Scale score, occlusion site, tandem lesion, collateral grade or thrombolysis. Conclusions Patients with low ASPECTS who are selected for EVT using demographic and clinical profiles similar to higher ASPECTS patients achieved comparable outcomes. [ABSTRACT FROM AUTHOR]

Background Analyses of the effect of pre-stroke functional levels on the outcome of endovascular therapy (EVT) have focused on the course of patients with moderate to substantial pre-stroke disability. The effect of complete freedom from pre-existing disability (modified Rankin Scale (mRS) 0) versus predominantly mild pre-existing disability/symptoms (mRS 1-2) has not been well delineated. Methods The HERMES meta-analysis pooled data from seven randomized trials that tested the efficacy of EVT. We tested for a multiplicative interaction effect of pre-stroke mRS on the relationship between treatment and outcomes. Ordinal regression was used to assess the association between EVT and 90-day mRS (primary outcome) in the subgroup of patients with pre-stroke mRS 1-2. Multivariable regression modeling was then used to test the effect of mild pre-stroke disability/symptoms on the primary and secondary outcomes (delta-mRS, mRS 0-2/5-6) compared with patients with pre-stroke mRS 0. Results We included 1764 patients, of whom 199 (11.3%) had pre-stroke mRS 1-2. No interaction effect of pre-stroke mRS on the relationship between treatment and outcome was observed. Patients with pre-stroke mRS 1-2 had worse outcomes than those with pre-stroke mRS 0 (adjusted common OR (acOR) 0.53, 95% CI 0.40 to 0.70). Nonetheless, a significant benefit of EVT was observed within the mRS 1-2 subgroup (cOR 2.08, 95% CI 1.22 to 3.55). Conclusions Patients asymptomatic/without disability prior to onset have better outcomes following EVT than patients with mild disability/symptoms. Patients with pre-stroke mRS 1-2, however, more often achieve good outcomes with EVT compared with conservative management. These findings indicate that mild pre-existing disability/symptoms influence patient prognosis after EVT but do not diminish the EVT treatment effect. [ABSTRACT FROM AUTHOR]

Background Early neurological deterioration (END) after endovascular treatment (EVT) in patients with anterior circulation acute ischemic stroke (AIS) is associated with poor outcome. END may remain unexplained by parenchymal hemorrhage (UnEND). We aim to analyze the risk factors of UnEND in the medical management (MM) and EVT arms of the HERMES study. Methods We conducted a post-hoc analysis of anterior AIS patients who underwent EVT for proximal anterior occlusions. Risk factors of UnEND, defined as a worsening of ≥4 points between baseline National Institutes of Health Stroke Scale (NIHSS) and NIHSS at 24 hours without hemorrhage, were compared between both arms using mixed logistic regression models adjusted for baseline characteristics. An interaction analysis between the EVT and MM arms for risk factors of UnEND was conducted. Results Among 1723 patients assessable for UnEND, 160 patients experienced an UnEND (9.3%), including 9.1% (78/854) in the EVT arm and 9.4% (82/869) in the MM arm. There was no significant difference in the incidence of UnEND between the two study arms. In the EVT population, independent risk factors of UnEND were lower baseline NIHSS, higher baseline glucose, and lower collateral grade. In the MM population, the only independent predictor of UnEND was higher baseline glucose. However, we did not demonstrate an interaction between EVT and MM for baseline factors as risk factors of UnEND. UnEND was, similarly in both treatment groups, a significant predictor of unfavorable outcome in both the EVT (p<0.001) and MM (p<0.001) arms. Conclusions UnEND is not an uncommon event, with a similar rate which ever treatment arm is considered. In the clinical scenario of AIS due to large vessel occlusion, no patient-related factor seems to increase the risk for UnEND when treated by EVT compared with MM. [ABSTRACT FROM AUTHOR]

Background Determining infarct progression rate in acute ischemic stroke (AIS) is important for patient triage, treatment decision-making, and outcome prognostication. Objective To estimate infarct progression rate in patients with AIS with large vessel occlusion (LVO) and determine its predictors and impact on clinical outcome. Methods Data are from the ESCAPE-NA1 Trial. Patients with AIS with time from last known well to randomization <6 hours and near-complete reperfusion following endovascular treatment were included. Infarct growth rate (mL/h) was estimated by dividing 24 hour infarct volume (measured by non-contrast CT or diffusion-weighted magnetic resonance imaging) by time from last known well to reperfusion. Multivariable linear regression was used to assess the association of patient baseline variables with log-transformed infarct progression rate. The association of infarct progression rate and good outcome (modified Rankin Scale score 0-2) was determined using multivariable logistic regression. Results Four hundred and nine patients were included in the study. Median infarct progression rate was 4.74 mL/h (IQR 1.25-14.84). Collateral status (β: -0.81 (95% CI -1.20 to -0.41)), Alberta Stroke Program Early CT Score (ASPECTS, β: -0.34 (95% CI -0.46 to -0.23)), blood glucose(β: 0.09 (95% CI 0.02 to 0.16)), and National Institutes of Health Stroke Scale (NIHS score (β: 0.07 (95% CI 0.04 to 0.10)) were associated with logtransformed infarct progression rate. Clinical and imaging baseline variables explained 23% of the variance in infarct progression rate. Infarct progression rate was significantly associated with good outcome (aOR per 1 mL/h increase: 0.96 (95% CI 0.95 to 0.98)). Conclusion In this sample of patients presenting within the early time window with LVO and nearcomplete recanalization, infarct progression rate was significantly associated with good outcome. A significant association between ASPECTS, collateral status, blood glucose, and NIHSS score was observed, but baseline imaging and clinical characteristics explained only a small proportion of the interindividual variance. More research on measurable factors affecting infarct growth is needed. [ABSTRACT FROM AUTHOR]

Background The optimal treatment and prognosis for stroke patients with tandem cervical carotid occlusion are unclear. We analyzed outcomes and treatment strategies of tandem occlusion patients in the ESCAPE-NA1 trial. Methods ESCAPE-NA1 was a multicenter international randomized trial of nerinetide versus placebo in 1105 patients with acute ischemic stroke who underwent endovascular treatment. We defined tandem occlusions as complete occlusion of the cervical internal carotid artery (ICA) on catheter angiography, in addition to a proximal ipsilateral intracranial large vessel occlusion. Baseline characteristics and outcome parameters were compared between patients with tandem occlusions versus those without, and between patients with tandem occlusion who underwent ICA stenting versus those who did not. The influence of tandem occlusions on functional outcome was analyzed using multivariable regression modeling. Results Among 115/1105 patients (10.4%) with tandem occlusions, 62 (53.9%) received stenting for the cervical ICA occlusion. Of these, 46 (74.2%) were stented after and 16 (25.8%) before the intracranial thrombectomy. A modified Rankin Score (mRS) of 0-2 at 90 days was achieved in 82/115 patients (71.3%) with tandem occlusions compared with 579/981 (59.5%) patients without tandem occlusions. Tandem occlusion did not impact functional outcome in the adjusted analysis (OR 1.5, 95% CI 0.95 to 2.4). Among the subgroup of patients with tandem occlusion, cervical carotid stenting was not associated with different outcomes compared with no stenting (mRS 0-2: 75.8% vs 66.0%, adjusted OR 2.0, 95% CI 0.8 to 5.1). Conclusions Tandem cervical carotid occlusion in patients with acute large vessel stroke did not lower the odds of good functional outcome in our study. Functional outcomes were similar irrespective of the management of the cervical ICA occlusion (stenting vs not stenting). [ABSTRACT FROM AUTHOR]

Background Patient age and baseline Alberta Stroke Program Early CT score (ASPECTS) are both independent predictors of outcome in acute ischemic stroke patients treated with endovascular therapy (EVT). We assessed the combined effect of age and ASEPCTS on clinical outcome in acute ischemic stroke patients with LVO with and without EVT, and EVT treatment effect in different age/ASPECTS subgroups. Methods The HERMES collaboration pooled data of seven randomized controlled trials that tested the efficacy of EVT. Adjusted logistic regression was performed to test for multiplicative interaction of age and ASPECTS with the primary outcome (ordinal mRS) and secondary outcomes (mRS 0-2/0-1/0-3) in the EVT and control arms. Patients were then stratified by age (<75 vs ≥ 75 years) and ASPECTS (0-5/6-7/8-10), and adjusted effect-size estimates for the association of EVT were derived for the six age/ASPECTS subgroups. Results 1735 patients were included in the analysis. There was no multiplicative interaction between age and ASPECTS on clinical outcomes. In the exploratory subgroup analysis, we found a nominally negative point estimate for the association of EVT with clinical outcome in the ASPECTS 0-5/age ≥75, subgroup (acOR 0.36, 95% CI 0.07 to 1.89). The point estimate for moderate outcome (mRS0-3) nominally favored EVT (aOR 1.24, 95% CI 0.16 to 9.84). In all other subgroups, effect size-estimates consistently favored EVT. Conclusion There was no multiplicative interaction of age and ASPECTS on clinical outcomes in EVT or control arm patients. Outcomes in patients ≥75 years with ASPECTS 0-5 were poor, irrespective of treatment. Further investigation to define the role of EVT and range of acceptable outcomes in this subgroup is warranted. [ABSTRACT FROM AUTHOR]

Background and purpose Infarct volume is a valuable outcome measure in treatment trials of acute ischemic stroke and is strongly associated with functional outcome. Its manual volumetric assessment is, however, too demanding to be implemented in clinical practice. Objective To assess the value of convolutional neural networks (CNNs) in the automatic segmentation of infarct volume in follow-up CT images in a large population of patients with acute ischemic stroke. Materials and methods We included CT images of 1026 patients from a large pooling of patients with acute ischemic stroke. A reference standard for the infarct segmentation was generated by manual delineation. We introduce three CNN models for the segmentation of subtle, intermediate, and severe hypodense lesions. The fully automated infarct segmentation was defined as the combination of the results of these three CNNs. The results of the three-CNNs approach were compared with the results from a single CNN approach and with the reference standard segmentations. Results The median infarct volume was 48 mL (IQR 15-125 mL). Comparison between the volumes of the three-CNNs approach and manually delineated infarct volumes showed excellent agreement, with an intraclass correlation coefficient (ICC) of 0.88. Even better agreement was found for severe and intermediate hypodense infarcts, with ICCs of 0.98 and 0.93, respectively. Although the number of patients used for training in the single CNN approach was much larger, the accuracy of the three-CNNs approach strongly outperformed the single CNN approach, which had an ICC of 0.34. Conclusion Convolutional neural networks are valuable and accurate in the quantitative assessment of infarct volumes, for both subtle and severe hypodense infarcts in follow-up CT images. Our proposed three-CNNs approach strongly outperforms a more straightforward single CNN approach. [ABSTRACT FROM AUTHOR]

Background and purpose Thromboembolic events are recognized complications of aneurysm coiling. Objective To identify any protective effects of antiplatelet therapy use before coiling of unruptured aneurysms. Methods We conducted a meta-analysis of clinical studies published up to February 2019. We included studies reporting symptomatic thromboembolic events (defined as clinical stroke or transient ischemic attacks) in patients who received antiplatelet therapy before coiling of unruptured aneurysms using unassisted coiling, balloon assistance, or multiple microcatheters. We excluded ruptured aneurysms and those treated with stent coiling or flow diverters. Results We identified 14 studies (2486 patients). All were single-center studies and four were prospective. In three studies with a control (no treatment) arm, the pooled risk ratio for symptomatic thromboembolic events with versus without antiplatelet therapy was 0.33 (95% CI 0.17 to 0.92, p= 0.035). The cumulative risk of symptomatic thromboembolic events with single antiplatelet agents was 5.0% '56/1122' (95% CI 1.6% to 8.4%, I²83.63%), and with dual or multiple agents 2.7% '33/1237' (95% CI 1.0% to 3.0%, I²39.9%). The incidence of diffusion lesions was reported in seven studies. It was 50.5% '96/190' (95% CI 7.3% to 93.9%, I²94.4%) with single agents compared with 43.9% '196/446' (95% CI 25.9% to 61.9%, I²73.4%) with dual or multiple agents. Conclusion Periprocedural antiplatelet therapy was associated with a low symptomatic thromboembolic event after coiling-only for unruptured aneurysms. However, available evidence is of limited quality with significant heterogeneity, requiring evidence from randomized controlled trials. [ABSTRACT FROM AUTHOR]

Background and purpose Differences in the treatment practice of female and male physicians have been shown in several medical subspecialties. It is currently not known whether this also applies to endovascular stroke treatment. The purpose of this study was to explore whether there are differences in endovascular treatment decisions made by female and male stroke physicians and neurointerventionalists. Methods In an international survey, stroke physicians and neurointerventionalists were randomly assigned 10 case scenarios and asked how they would treat the patient: (A) assuming there were no external constraints and (B) given their local working conditions. Descriptive statistics were used to describe baseline demographics, and the adjusted OR for physician gender as a predictor of endovascular treatment decision was calculated using logistic regression. Results 607 physicians (97 women, 508 men, 2 who did not wish to declare) participated in this survey. Physician gender was neither a significant predictor for endovascular treatment decision under assumed ideal conditions (endovascular therapy was favored by 77.0% of female and 79.3% of male physicians, adjusted OR 1.03, P=0.806) nor under current local resources (endovascular therapy was favored by 69.1% of female and 76.9% of male physicians, adjusted OR 1.03, P=0.814). Conclusion Endovascular therapy decision making between male and female physicians did not differ under assumed ideal conditions or under current local resources. [ABSTRACT FROM AUTHOR]

Background and purpose The decision to proceed with endovascular thrombectomy should ideally be made independent of inconvenience factors, such as daytime. We assessed the influence of patient presentation time on endovascular therapy decision making under current local resources and assumed ideal conditions in acute ischemic stroke with level 2B evidence for endovascular treatment. Methods and materials In an international cross sectional survey, 607 stroke physicians from 38 countries were asked to give their treatment decisions to 10 out of 22 randomly assigned case scenarios. Eleven scenarios had level 2B evidence for endovascular treatment: 7 daytime scenarios (7:00 am-5:00 pm) and four night time cases (5:01 pm- 6:59 am). Participants provided their treatment approach assuming (A) there were no practice constraints and (B) under their current local resources. Endovascular treatment decisions in the 11 scenarios were analyzed according to presentation time with adjustment for patient and physician characteristics. results Participants selected endovascular therapy in 74.2% under assumed ideal conditions, and 70.7% under their current local resources of night time scenarios, and in 67.2% and 63.8% of daytime scenarios. Night time presentation did not increase the probability of a treatment decision against endovascular therapy under current local resources or assumed ideal conditions. Conclusion Presentation time did not influence endovascular treatment decision making in stroke patients in this international survey. [ABSTRACT FROM AUTHOR]

Background Revascularization after endovascular therapy for acute ischemic stroke is measured by the Thrombolysis in cerebral infarction (TICI) scale, yet variability exists in scale definitions. We examined the degree of reperfusion with the expanded Tici (eTICI) scale and association with outcomes in the HERMES collaboration of recent endovascular trials. Methods The HERMES imaging core, blind to all other data, evaluated angiography after endovascular therapy in HERMES. A battery of Tici scores (mTICI, TICI, TICI2C) was used to define reperfusion of the initial target occlusion defined by non-invasive imaging and conventional angiography. Results Angiography of 801 subjects was available, including 797 defined by non-invasive imaging (154 internal carotid artery (icA), 583 M1, 60 M2) and 748 by conventional angiography (195 icA, 459 M1, 94 M2). Among 729 subjects in whom the reperfusion grade could be established, using eTici (3=100%, 2c=90-99%, 2b67=67-89%, 2b50=50-66%) of the conventional angiography target occlusion, there were 63 eTICI 3 (9%), 166 eTICI 2c (23%), 218 eTici 2b67 (30%), 103 eTICI 2b50 (14%), 100 eTICI 2a (14%), 19 eTICI 1 (3%), and 60 eTICI 0 (8%). Modified Rankin scale shift analyses from baseline to 90 days showed that increasing Tici grades were linked with better outcomes, with significant distinctions between Tici 0/1 versus 2a (p=0.028), 2a versus 2b50 (p=0.017), and 2b50 versus 2b67 (p=0.014). Conclusions The benefit of endovascular therapy in HERMEs was strongly associated with increasing degrees of reperfusion defined by eTici. The eTici metric identified meaningful distinctions in clinical outcomes and may be used in future studies and routine practice. [ABSTRACT FROM AUTHOR]

Background Whether pretreatment with intravenous thrombolysis prior to mechanical thrombectomy (IVT+MTE) adds additional benefit over direct mechanical thrombectomy (dMTE) in patients with large vessel occlusions (LVO) is a matter of debate. Methods This study-level meta-analysis was presented in accord with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled effect sizes were calculated using the inverse variance heterogeneity model and displayed as summary Odds Ratio (s0R) and corresponding 95% confidence interval (95% Cl). Sensitivity analysis was performed by distinguishing between studies including dMTE patients eligible for IVT (IVT-E) or ineligible for IVT (IVT-IN). Primary outcome measures were functional independence (modified Rankin Scale ≤2) and mortality at day 90, successful reperfusion, and symptomatic intracerebral hemorrhage. Results Twenty studies, incorporating 5279 patients, were included. There was no evidence that rates of successful reperfusion differed in dMTE and IVT+MTE patients (sOR 0.93, 95% Cl 0.68 to 1.28). In studies including IVT-IN dMTE patients, patients undergoing dMTE tended to have lower rates of functional independence and had higher odds for a fatal outcome as compared with IVT+MTE patients (sOR 0.78, 95% Cl 0.61 to 1.01 and sOR 1.45, 95% CI 1.22 to 1.73). However, no such treatment group effect was found when analyses were confined to cohorts with a lower risk of selection bias (including IVT-E dMTE patients). Conclusion The quality of evidence regarding the relative merits of IVT+MTE versus dMTE is low. When considering studies with lower selection bias, the data suggest that dMTE may offer comparable safety and efficacy as compared with IVT+MTE. The conduct of randomized-controlled clinical trials seems justified. [ABSTRACT FROM AUTHOR]

Background Tandem occlusions of the extracranial carotid and intracranial carotid or middle cerebral artery have a particularly poor prognosis without treatment. Several management strategies have been used with no clear consensus recommendations. We examined subjects with tandem occlusions enrolled in the EScAPE trial and their outcomes. Methods Data are from the EScAPE trial. Additional data were sought on interventions for each subject. results There were 54 (17%) subjects with tandem extracranial and intracranial occlusions. Patients in the endovascular treatment arm (n=30) were more likely to be younger (median age 66 years, p<0.01), male (66.7%, p=0.03), diabetic, and without atrial fibrillation. Subjects with tandem occlusions were more likely to have intracranial internal carotid artery occlusions than M1 occlusions (p<0.01). Of the 30 intervention-arm subjects, 17 (57%) underwent emergency endovascular treatment of the extracranial disease, 10 subjects before and seven subjects after intracranial thrombectomy. Of the remaining 13 subjects, only four required staged carotid revascularization due to persistent severe carotid stenosis; four had cervical pseudo-occlusions with no residual stenosis after large distal carotid thrombus burden aspiration/retrieval. Outcomes were similar between subjects with and without tandem lesions. The use of antithrombotic agents after acute carotid artery stenting was variable but no symptomatic intracerebral hemorrhage was seen in subjects who underwent emergency endovascular treatment of extracranial carotid artery. Conclusions Tandem occlusions occurred in one-sixth of patients and were treated highly variably within the EScAPE trial. While outcomes were similar, the best method to treat the carotid artery in patients with tandem occlusion awaits further randomized data. [ABSTRACT FROM AUTHOR]

Background A recent randomized trial of patients with primarily anterior circulation intracranial artery stenosis showed that intensive medical therapy was superior to intracranial stenting in preventing recurrent stroke. The rate of stroke recurrence or death in symptomatic intracranial vertebrobasilar stenosis with medical therapy alone may be especially high, and rates compared with endovascular therapy need further study. Methods We conducted a systematic review and meta-analysis of studies reporting the rates of stroke recurrence or death (the primary outcome) in symptomatic intracranial vertebrobasilar stenosis with medical or endovascular treatment over a minimum follow-up period of 6 months. We included all studies in any language indexed in MEDLINE or EMBASE, supplemented by bibliography searches and by contacting the authors. The secondary endpoints were stroke recurrence, and basilar artery and vertebral artery stroke recurrence rates. Results 23 studies (592 medical treatment patients and 480 endovascular treatment patients) were included. The risk of combined stroke recurrence or death was 14.8 per 100 person-years (95% CI 9.5 to 20.1) in the medical group compared with 8.9 per 100 person-years (95% CI 6.9 to 11.0) in the endovascular group. The incidence rate ratio was 1.3 (95% CI 1.0 to 1.7). The stroke recurrence rate was 9.6 per 100 person-years (95% CI 5.1 to 14.1) in the medical group compared with 7.2 per 100 person-years (95% CI 5.5 to 9.0) in the endovascular group. Conclusions Our results showed that the risk of stroke recurrence or death or the risk of stroke recurrence alone was comparable between the medical and endovascular therapy groups. A small preventive effect of endovascular therapy may exist, particularly if the 30 day postprocedural risk is reduced. [ABSTRACT FROM AUTHOR]

While the overall complication rates for endovascular treatment for acute stroke has been extremely low in recent trials, it is important to separate out and accurately document complications. One of these complications that is usually related to the endovascular intervention is Infarct in New Territory (INT). We propose a standardized methodology for documenting INT after the procedure. This new classification takes into account variations in vascular anatomy and location of the occlusion. In addition, given that after the recent trials, vascular imaging (eg, CT angiography (CTA)) is now the standard of care in the work up of acute ischemic stroke, this classification utilizes the information on the pre- procedure non-invasive vascular imaging, the angiography images from end of procedure and the location of lesions on the follow-up scan. [ABSTRACT FROM AUTHOR]